1. Field of the Invention
The invention relates to a device for transferring an optical element, and more particularly, to a device for transferring an optical element configured to realize both an auto focusing (AF) function for automatically moving an optical element such as a lens, and a manual focusing (MF) function for allowing a user to manipulate focus.
2. Description of the Related Art
A digital photographing apparatus such as a camera or camcorder has a function for adjusting the focus or zoom by moving the position of an optical element such as a lens. In general, there are two types of focusing functions: an AF function for automatically adjusting the position of a lens to obtain a correct focus without a user's separate manipulation, and a MF function for manually adjusting the position of a lens by fine tuning a focus with a user's eyes.
With wide dissemination of digital photographing devices, there is a need for a function that allows a user to freely adjust the position of a lens as desired at any time. Conventionally, to implement such a function, a separate switch, which allows a user to select between AF mode and MF mode, is provided. However, this approach may cause inconvenience of manipulating the switch.
Furthermore, in order to realize both AF and MF functions, mechanical elements having a complicated structure and a large volume need to be employed to connect or block a driving force generated by a driving element for performing an AF function.
While an AF feature is convenient for taking pictures, it may be difficult to fine tune the position of a lens like in an MF mode. When the AF function is set to fine tune the position of a lens, however, a user may have to rotate an MF ring over a wide angular range in an MF mode. Another drawback is that it may be difficult to hold a camera when the MF ring also rotates while the AF function is being performed.